In recent years, a mobile terminal has been developed that has a program executing environment. An example of a mobile terminal of this type is one that has a Java virtual machine. The user installs a program in the mobile terminal, and thus can add a desired function to the mobile terminal.
However, even if desirable functions are added to a mobile terminal, a user is likely to become tired of using the same mobile terminal after a protracted period of time. On the other hand, the mobile terminal industry experiences fierce competition and various new products that are attractive to users have been successively placed on the market. A user may want to replace his mobile terminal with a new desirable product that has been placed on the market. Once the mobile terminal is replaced, however, the functions that have been previously added to the old mobile terminal cannot be used any longer. If the same functions are to be used even after replacement of a mobile terminal, the programs that have been installed in the old mobile terminal have to be installed in the new mobile terminal. This may be difficult.